Chemotherapy, radiation therapy, as well as targeted anticancer agents can induce clinically relevant tumor-targeting immune responses, which critically rely on the antigenicity of malignant cells and their capacity to generate adjuvant signals. In particular, immunogenic cell death (ICD) is accompanied by the exposure and release of numerous damage-associated molecular patterns (DAMPs), which altogether confer a robust adjuvanticity to dying cancer cells, as they favor the recruitment and activation of antigen-presenting cells. ICD-associated DAMPs include surface-exposed calreticulin (CALR) as well as secreted ATP, annexin A1 (ANXA1), type I interferon, and high-mobility group box 1 (HMGB1). Additional hallmarks of ICD encompass the phosphorylation of eukaryotic translation initiation factor 2 subunit-α (EIF2S1, better known as eIF2α), the activation of autophagy, and a global arrest in transcription and translation. Here, we outline methodological approaches for measuring ICD markers in vitro and ex vivo for the discovery of next-generation antineoplastic agents, the development of personalized anticancer regimens, and the identification of optimal therapeutic combinations for the clinical management of cancer.

• MeSH
• Immunogenic Cell Death immunology   MeSH
• Immunotherapy methods   MeSH
• Humans MeSH
• Neoplasms therapy   MeSH
• Drug Discovery methods   MeSH
• Check Tag
• Humans MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Review MeSH

BACKGROUND: Adjuvanticity, which is the ability of neoplastic cells to deliver danger signals, is critical for the host immune system to mount spontaneous and therapy-driven anticancer immune responses. One of such signals, i.e., the exposure of calreticulin (CALR) on the membrane of malignant cells experiencing endoplasmic reticulum (ER) stress, is well known for its role in the activation of immune responses to dying cancer cells. However, the potential impact of CALR on the immune contexture of primary and metastatic high-grade serous carcinomas (HGSCs) and its prognostic value for patients with HGSC remains unclear. METHOD: We harnessed a retrospective cohort of primary (no = 152) and metastatic (no = 74) tumor samples from HGSC patients to investigate the CALR expression in relation with prognosis and function orientation of the tumor microenvironment. IHC data were complemented with transcriptomic and functional studies on second prospective cohort of freshly resected HGSC samples. In silico analysis of publicly available RNA expression data from 302 HGSC samples was used as a confirmatory approach. RESULTS: We demonstrate that CALR exposure on the surface of primary and metastatic HGSC cells is driven by a chemotherapy-independent ER stress response and culminates with the establishment of a local immune contexture characterized by TH1 polarization and cytotoxic activity that enables superior clinical benefits. CONCLUSIONS: Our data indicate that CALR levels in primary and metastatic HGSC samples have robust prognostic value linked to the activation of clinically-relevant innate and adaptive anticancer immune responses.

• Keywords
• B cells, CD20, Cancer immunotherapy, DC-LAMP, Dendritic cells, Immunogenic cell death,
• MeSH
• Adult MeSH
• Calreticulin immunology   MeSH
• Middle Aged MeSH
• Humans MeSH
• Tumor Microenvironment genetics   immunology   MeSH
• Ovarian Neoplasms genetics   immunology   MeSH
• Prognosis MeSH
• RNA-Seq MeSH
• Aged, 80 and over MeSH
• Aged MeSH
• Endoplasmic Reticulum Stress MeSH
• Check Tag
• Adult MeSH
• Middle Aged MeSH
• Humans MeSH
• Aged, 80 and over MeSH
• Aged MeSH
• Female MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Research Support, U.S. Gov't, Non-P.H.S. MeSH
• Names of Substances
• CALR protein, human MeSH Browser
• Calreticulin MeSH

Cytokines regulate virtually aspects of innate and adaptive immunity, including the initiation, execution and extinction of tumor-targeting immune responses. Over the past three decades, the possibility of using recombinant cytokines as a means to elicit or boost clinically relevant anticancer immune responses has attracted considerable attention. However, only three cytokines have been approved so far by the US Food and Drug Administration and the European Medicines Agency for use in cancer patients, namely, recombinant interleukin (IL)-2 and two variants of recombinant interferon alpha 2 (IFN-α2a and IFN-α2b). Moreover, the use of these cytokines in the clinics is steadily decreasing, mostly as a consequence of: (1) the elevated pleiotropism of IL-2, IFN-α2a and IFN-α2b, resulting in multiple unwarranted effects; and (2) the development of highly effective immunostimulatory therapeutics, such as immune checkpoint blockers. Despite this and other obstacles, research in the field continues as alternative cytokines with restricted effects on specific cell populations are being evaluated. Here, we summarize research preclinical and clinical developments on the use of recombinant cytokines for immunostimulation in cancer patients.

• Keywords
• CAR T cells, CTLA4, GM-CSF, IL-15, PD-1, pembrolizumab,
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Review MeSH

Immune checkpoint blockers (ICBs) are literally revolutionizing the clinical management of an ever more diversified panel of oncological indications. Although considerable attention persists around the inhibition of cytotoxic T lymphocyte-associated protein 4 (CTLA4) and programmed cell death 1 (PDCD1, best known as PD-1) signaling, several other co-inhibitory T-cell receptors are being evaluated as potential targets for the development of novel ICBs. Moreover, substantial efforts are being devoted to the identification of biomarkers that reliably predict the likelihood of each patient to obtain clinical benefits from ICBs in the absence of severe toxicity. Tailoring the delivery of specific ICBs or combinations thereof to selected patient populations in the context of precision medicine programs constitutes indeed a major objective of the future of ICB-based immunotherapy. Here, we discuss recent preclinical and clinical advances on the development of ICBs for oncological indications.

• Keywords
• Atezolizumab, avelumab, durvalumab, ipilimumab, nivolumab, pembrolizumab,
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Review MeSH

BACKGROUND: Locoregionally advanced, recurrent, and metastatic squamous cell carcinomas of the head and neck (SCCHN) remain difficult to treat disease entities, in which systemic treatment often forms an integral part of their management. Immunotherapy is based on functional restoration of the host immune system, helping to counteract various tumour evasion strategies. Broadly, immunotherapeutic approaches encompass tumour-specific antibodies, cancer vaccines, cytokines, adoptive T-cell transfer, and immune-modulating agents. Until 2015, the epidermal growth factor receptor inhibitor cetuximab, a tumour-specific antibody, represented the only Food and Drug Administration (FDA)-approved targeted therapy for SCCHN. Subsequently, in 2016, the results from two prospective trials employing the immune-modulating antibodies nivolumab and pembrolizumab heralded a new era of anticancer treatment. DISCUSSION: Nivolumab and pembrolizumab are monoclonal antibodies against programmed cell death protein-1 (PD-1), an 'immune checkpoint' receptor. Found on the surface of T-cells, PD-1 negatively regulates their activation and can thus be exploited during carcinogenesis. The second-line phase III trial CheckMate-141 randomly assigned 361 patients with recurrent and/or metastatic SCCHN in a 2:1 ratio to receive either single-agent nivolumab (3 mg/kg intravenously every 2 weeks) or standard monotherapy (methotrexate, docetaxel, or cetuximab). Nivolumab improved the objective response rate (13% versus 6%) and median overall survival (OS; 7.5 versus 5.1 months, p = 0.01) without increasing toxicity. Exploratory biomarker analyses indicated that patients treated with nivolumab had longer OS than those given standard therapy, regardless of tumour PD-1 ligand (PD-L1) expression or p16 status. In the non-randomised, multicohort phase Ib study KEYNOTE-012, treatment with pembrolizumab achieved comparable results. Importantly, most of the responding patients had a long-lasting response. CONCLUSION: Based on recent results, nivolumab and pembrolizumab have been approved by the FDA as new standard-of-care options for the second-line treatment of recurrent and/or metastatic SCCHN. Generally well tolerated, these novel drugs demonstrated modest response rates, with tumour regressions usually being durable, even in platinum-resistant/refractory cases. The next step will be to extend the observed benefit to first-line treatment, currently dominated by the EXTREME regimen (platinum/5-fluorouracil/cetuximab), and to the locoregionally advanced setting, where concurrent chemoradiation with cisplatin is standard. Regimens combining immunotherapy with other modalities will probably further improve outcomes.

• Keywords
• Biomarkers, Cetuximab, Combination regimen, Head and neck cancer, Immunotherapy, Metastatic, Nivolumab, Pembrolizumab, Recurrent, Targeted therapy,
• MeSH
• Squamous Cell Carcinoma of Head and Neck MeSH
• Immunotherapy * methods   MeSH
• Humans MeSH
• Head and Neck Neoplasms therapy   MeSH
• Prospective Studies MeSH
• Carcinoma, Squamous Cell therapy   MeSH
• Check Tag
• Humans MeSH
• Publication type
• Journal Article MeSH

Cancer cell death can be perceived as immunogenic by the host only when malignant cells emit immunostimulatory signals (so-called "damage-associated molecular patterns," DAMPs), as they die in the context of failing adaptive responses to stress. Accumulating preclinical and clinical evidence indicates that the capacity of immunogenic cell death to (re-)activate an anticancer immune response is key to the success of various chemo- and radiotherapeutic regimens. Malignant blasts from patients with acute myeloid leukemia (AML) exposed multiple DAMPs, including calreticulin (CRT), heat-shock protein 70 (HSP70), and HSP90 on their plasma membrane irrespective of treatment. In these patients, high levels of surface-exposed CRT correlated with an increased proportion of natural killer cells and effector memory CD4+ and CD8+ T cells in the periphery. Moreover, CRT exposure on the plasma membrane of malignant blasts positively correlated with the frequency of circulating T cells specific for leukemia-associated antigens, indicating that ecto-CRT favors the initiation of anticancer immunity in patients with AML. Finally, although the levels of ecto-HSP70, ecto-HSP90, and ecto-CRT were all associated with improved relapse-free survival, only CRT exposure significantly correlated with superior overall survival. Thus, CRT exposure represents a novel powerful prognostic biomarker for patients with AML, reflecting the activation of a clinically relevant AML-specific immune response.

• MeSH
• Leukemia, Myeloid, Acute drug therapy   genetics   immunology   metabolism   MeSH
• Alarmins metabolism   MeSH
• Blast Crisis immunology   pathology   MeSH
• Cell Death MeSH
• CD8-Positive T-Lymphocytes immunology   MeSH
• Phenotype MeSH
• Transcription, Genetic MeSH
• Immunity MeSH
• Calreticulin metabolism   MeSH
• Middle Aged MeSH
• Humans MeSH
• Multivariate Analysis MeSH
• Proportional Hazards Models MeSH
• HSP70 Heat-Shock Proteins metabolism   MeSH
• HSP90 Heat-Shock Proteins metabolism   MeSH
• Gene Expression Regulation, Leukemic MeSH
• Gene Expression Profiling MeSH
• Th1 Cells immunology   MeSH
• Treatment Outcome MeSH
• Check Tag
• Middle Aged MeSH
• Humans MeSH
• Male MeSH
• Female MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• Alarmins MeSH
• CALR protein, human MeSH Browser
• Calreticulin MeSH
• HSP70 Heat-Shock Proteins MeSH
• HSP90 Heat-Shock Proteins MeSH

The immunogenicity of malignant cells has recently been acknowledged as a critical determinant of efficacy in cancer therapy. Thus, besides developing direct immunostimulatory regimens, including dendritic cell-based vaccines, checkpoint-blocking therapies, and adoptive T-cell transfer, researchers have started to focus on the overall immunobiology of neoplastic cells. It is now clear that cancer cells can succumb to some anticancer therapies by undergoing a peculiar form of cell death that is characterized by an increased immunogenic potential, owing to the emission of the so-called "damage-associated molecular patterns" (DAMPs). The emission of DAMPs and other immunostimulatory factors by cells succumbing to immunogenic cell death (ICD) favors the establishment of a productive interface with the immune system. This results in the elicitation of tumor-targeting immune responses associated with the elimination of residual, treatment-resistant cancer cells, as well as with the establishment of immunological memory. Although ICD has been characterized with increased precision since its discovery, several questions remain to be addressed. Here, we summarize and tabulate the main molecular, immunological, preclinical, and clinical aspects of ICD, in an attempt to capture the essence of this phenomenon, and identify future challenges for this rapidly expanding field of investigation.

• Keywords
• anti-tumor immunity, immunogenicity, immunotherapy, molecular medicine, oncoimmunology, patient prognosis, translational medicine,
• Publication type
• Journal Article MeSH

It is now clear that human neoplasms form, progress, and respond to therapy in the context of an intimate crosstalk with the host immune system. In particular, accumulating evidence demonstrates that the efficacy of most, if not all, chemo- and radiotherapeutic agents commonly employed in the clinic critically depends on the (re)activation of tumor-targeting immune responses. One of the mechanisms whereby conventional chemotherapeutics, targeted anticancer agents, and radiotherapy can provoke a therapeutically relevant, adaptive immune response against malignant cells is commonly known as "immunogenic cell death." Importantly, dying cancer cells are perceived as immunogenic only when they emit a set of immunostimulatory signals upon the activation of intracellular stress response pathways. The emission of these signals, which are generally referred to as "damage-associated molecular patterns" (DAMPs), may therefore predict whether patients will respond to chemotherapy or not, at least in some settings. Here, we review clinical data indicating that DAMPs and DAMP-associated stress responses might have prognostic or predictive value for cancer patients.

• Keywords
• ATP, ER stress response, HSPs, autophagy, calreticulin, type I interferon,
• Publication type
• Journal Article MeSH
• Review MeSH